A few years ago, Judith Martin — a k a Miss Manners — began noticing a peculiar side effect of the flagging economy. Although she’d always received mail from people seeking advice on how to handle workplace breaches of etiquette, the questions began arriving in her inbox with increasing frequency and urgency.

“Over the last couple of decades, the personalization of the office changed dramatically … there’s an informality people often take for the absence of rules — which it’s not,” she says. “People read informality as, ‘Do whatever you feel like,’ and whatever you feel like might be disastrous.”

So Martin and her son, Nicholas Ivor Martin, collaborated on a book, “Miss Manners Minds Your Business,” that they hope will help employees maintain professionalism and courtesy in the workplace. Read on for some of their top tips:

FOR THE JOB SEEKER

As candidness becomes more valued in the workplace, some interviewees are faced with intrusive questions about personal obstacles. “There’s an awful lot that’s been put into convincing people that putting your best foot forward is showing what an honest person you are,” says Nicholas, “which means airing all the laundry and all the terrible things that have happened in your life.”

The bottom line:

“Your personal life and your business life are separate,” he says. If asked about your personal life, either deflect the question, or think about what the interviewer is trying to get at — for example, your honesty or depth of experience — and answer “without crossing that boundary into talking about your love life in a job interview.”

FOR THE WORKER IRRITATED BY THE OPEN-OFFICE PLAN

“The idea of the big open space was originally the very charming, but false, notion that if people know each other and are close, they will love each other,” Miss Manners observes. She fields droves of complaints from employees who have been subjected to their open-plan office mates’ odors, conversations and nosiness.

The bottom line:

Delicacy is key in such close quarters. If you have to speak up, “give the person a dignified, face-saving way out,” Miss Manners says. “Say, ‘I’m sorry, you probably don’t realize that in this close space, everybody can’t help hearing about your problems with your girlfriend when you’re talking on the phone.’ ”

FOR THE WORKER WHOSE PERSONAL LIFE IS CONSUMED BY HIS PROFESSIONAL LIFE

Thanks to advances in technology and evolutions in workplace culture, there’s now an expectation that the professional takes priority over the personal, whether that means an employee should be available on e-mail at all times, or that co-workers organize a near-constant stream of happy hours and work parties. But “jobs are not forever,” notes Miss Manners. “What are you working for? You’re working for the ability to have a pleasant life, and it’s not a pleasant life if you have divested yourself of your other ties.”

The bottom line:

At least some of your co-workers would probably also prefer more free time. Enlist them in opting out of some of the social activities in favor of completing your assigned tasks. And stop checking e-mail at home if possible. “The usual situation is that the employee puts more emphasis than necessary on being immediately available,” Miss Manners says. “Sure, you want to get the work done, but maybe if you stopped playing games while you were at the office, you could get it done then.”

FOR THE WORKER CONFUSED BY GIFT-GIVING ETIQUETTE

Miss Manners heartily disapproves of the workplace Secret Santa. “Why are people giving presents in the workplace at all?” she wonders. “Presents are symbolic. When you give them in your personal life, they should show that you are paying attention to the person to whom you’re giving them. Knowing all those things about your co-workers, unless they also happen to be your friends or your relatives, would be a little bit impertinent.” Each holiday season, she receives queries from people who don’t know what to give to their assigned recipient, as well as from “people who are highly offended by what they’ve received.” Added to that, many workers don’t have the personal resources to buy an additional gift for a work acquaintance on top of their holiday expenses.

The bottom line:

It is possible to abstain from this year’s Secret Santa without looking like a Grinch. “Learn graceful ways of saying no and of pointing out that this pressure to do something is not in line with most people’s wishes,” Miss Manners says. “I would enlist others in understanding why you’re opting out, or else take your vacation at that time.”